Methods For Recovering Hydrocarbon Materials From Subterranean Formations

ABSTRACT

A method for recovering hydrocarbon material from a subterranean formation includes introducing a treatment fluid into the subterranean formation. One treatment fluid includes at least one organometallic material having a metal or metalloid from Group III of the Periodic Table or a transition metal. An optional second fluid having an organophosphorous material can also be introduced. Another treatment fluid includes the reaction product of a transition metal compound and a silicon-containing material.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates generally to the recovery of hydrocarbonmaterials, such as oil and natural gas, from subterraneanhydrocarbon-bearing formations and, more particularly, to treatmentfluids useful to improve the production of hydrocarbon materialstherefrom.

Technical Considerations

Vast quantities of hydrocarbon materials (“hydrocarbons”), such as oiland natural gas, remain locked in subterranean rock formationsthroughout the world. These hydrocarbon materials are typicallyconcentrated in seams, i.e., narrow cracks and fissures, in theformation and remain trapped there by capillary pressure. One way tounlock these hydrocarbon materials is through the process of hydraulicfracturing or “fracking”. In fracking, a wellbore is drilled verticallyto the level of the subterranean formation and then horizontally througha portion of the formation. An aqueous fracking fluid is injected athigh pressure into the wellbore. This high pressure fluid expands or“fractures” the fissures to release the hydrocarbon materials, allowingthese materials to flow through these newly created fractures to thewellbore and then through the wellbore back to the surface.

The fractures produced by hydraulic fracturing are relatively narrow,typically on the order of about 1 millimeter (mm). Since the fracturesare narrow, the fracking fluid typically contains a proppant (such assand) to hold the fractures open when the fluid is removed.

The fracking fluid may also contain a surfactant to lower theinterfacial tension between the hydrocarbon material and the surroundingmedia. As will be appreciated by those skilled in the art, surfactantsadhere at the hydrocarbon/media interface to reduce the interfacialtension between the two phases and allow the hydrocarbon material toflow more easily through the narrow fractures. However, this means thatthe adhered surfactant is by design removed along with the hydrocarbonmaterial. As the surfactant level decreases, the interfacial tensionbetween the remaining hydrocarbon/media increases. Since capillarypressure is proportional to interfacial tension, as the surfactant isdepleted, the capillary pressure increases and it becomes harder andharder for the hydrocarbon material to flow through the narrowfractures. In addition to the surfactant removed with the hydrocarbonmaterial, since conventional surfactants are generally water soluble, aportion of the injected surfactant may simply be washed away as the highpressure aqueous fracking fluid flows through the formation.

A particular concern with the recovery of gaseous hydrocarbons (such asnatural gas) is the accumulation of water in the fractures. This watercould be water remaining from the fracking fluid or could be from thesurrounding geological area. This accumulated water (conventionallyreferred to as a “water block”) reduces the effective permeability ofthe formation by blocking or reducing the flow of the gas through thefracture. If the drainage rate for the accumulated water from thefractures is low, the water blocks could remain in place for an extendedperiod of time. As a result, gas recovery from the well can be reducedor completely stopped.

Therefore, it would be advantageous to provide a method of recoveringhydrocarbon material from subterranean formations which reduces orovercomes at least some of the drawbacks of conventional hydrocarbonrecovery methods. For example, it would be advantageous to provide arecovery method and/or composition that allows for decreased capillarypressure in the fractures even when the soluble surfactant levelsdecrease. It would also be advantageous to provide a method and/orcomposition that decreases water blocking of the fractures.

SUMMARY OF THE INVENTION

A method for recovering hydrocarbon material from a subterraneanformation comprises introducing at least one treatment fluid into thesubterranean formation. The at least one treatment fluid is introducedbefore or after a fracking fluid. The treatment fluid comprises at leastone organometallic material. Examples of organometallic materialsinclude one or more metals or metalloids selected from Group III of thePeriodic Table and transition metals: The organometallic material caninclude a C1 to C18 alkoxide group.

An optional second treatment fluid comprising an organophosphorousmaterial can also be introduced into the subterranean formation. Thesecond treatment fluid can be introduced before or after the frackingfluid. In one embodiment, the optional second treatment fluid, ifpresent, is introduced after the treatment fluid containing theorganometallic material. Examples of the organophosphorous materialinclude organophosphoric acid, organophosphonic acid, organophosphinicacid, and derivatives thereof.

Another method for recovering hydrocarbon material from a subterraneanformation comprises introducing a first treatment fluid into thesubterranean formation. The first treatment fluid comprises anorganometallic material. The organometallic material comprises at leastone metal or metalloid selected from the group consisting of members ofGroup III of the Periodic Table, and transition metals of Groups IIIB,IVB, VB and VIB of the Periodic Table. The organometallic material alsocomprises a C1 to C18 alkoxide group. A second treatment fluid is alsointroduced into the subterranean formation. The second treatment fluidcomprises an organophosphorous material, wherein the organophosphorousmaterial comprises an organophosphorous acid or derivative thereofcomprising at least one group selected from the group consisting of analiphatic group, an olefinic group, and an aryl-substitute group. Thefirst treatment fluid and second treatment fluid are introduced eitherbefore or after a fracking fluid. In one preferred embodiment, thesecond treatment fluid is introduced after the first treatment fluid.

A further method for recovering hydrocarbon material from a subterraneanformation comprises introducing at least one treatment fluid into thesubterranean formation. The at least one treatment fluid comprises amaterial comprising the reaction product of a transition metal compoundand a silicon-containing material. Examples of the transition metalcompound include transition metals from Period 6 of the Periodic Tableof Elements. Further specific examples of transition metals include La,Hf, Ta, W, Nb, and transition metals having electrons in the f orbital.

An additional method for recovering hydrocarbon material from asubterranean formation comprises introducing a first treatment fluidcomprising divalent metal cations into the subterranean formation andintroducing a second treatment fluid into the subterranean formation.The second treatment fluid comprises the reaction product of atransition metal compound and a silicon-containing material. The firsttreatment fluid and/or the second treatment fluid can be introducedeither before or after a fracking fluid.

A composition for treating subterranean hydrocarbon-bearing formationscomprises the reaction product of a transition metal compound and asilicon-containing material. The reaction product is configured toreduce the capillary pressure in fractures in the formation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein, all numbers expressing dimensions, physicalcharacteristics, processing parameters, quantities of ingredients,reaction conditions, and the like, used in the specification and claimsare to be understood as being modified in all instances by the term“about”. Accordingly, unless indicated to the contrary, the numericalvalues set forth in the following specification and claims may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical value should at least be construed in light of the numberof reported significant digits and by applying ordinary roundingtechniques. Moreover, all ranges disclosed herein are to be understoodto encompass the beginning and ending range values and any and allsubranges subsumed therein. For example, a stated range of “1 to 10”should be considered to include any and all subranges between (andinclusive of) the minimum value of 1 and the maximum value of 10; thatis, all subranges beginning with a minimum value of 1 or more and endingwith a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5, 5.5 to10, and the like. Additionally, all documents, such as but not limitedto, issued patents and patent applications, referred to herein are to beconsidered to be “incorporated by reference” in their entirety. Anyreference to amounts, unless otherwise specified, is “by weightpercent”. The terms “polymer” or “polymeric” include oligomers,homopolymers, copolymers, and terpolymers, e.g., polymers formed fromtwo or more types of monomers or polymers. The term “film” is used todescribe an area of a particular composition or material. The film neednot be a continuous film but could be formed by discrete areas of thecomposition or material.

The present invention relates to methods and compositions for increasingthe production of hydrocarbon materials, such as oil and natural gas,from subterranean formations. The invention will be described withreference to use in a conventional fracking operation. However, it is tobe understood that the invention is not limited to fracking but could beused in any enhanced oil or gas recovery system.

In a typical fracking operation, a well bore is drilled into ahydrocarbon-containing subterranean formation and high-pressure frackingfluid is injected into the formation. However, in the practice of theinvention, a treatment fluid of the invention is injected into theformation either before or after the fracking fluid. In anotherexemplary practice of the invention, a treatment fluid comprising acomposition of the invention can be injected separately from thefracking fluid (such as before or after the fracking fluid) or can be isincluded in the fracking fluid.

As will be appreciated by one skilled in the art, large portions ofsubterranean hydrocarbon-bearing formations are composed ofsilicate-based rock. Without being limited by theory, it is believedthat the materials of the invention adsorb or chemically bond with therock surfaces, e.g., the walls of the fractures. This lowers the surfaceenergy between the rock surfaces and the hydrocarbon materials, whichreduces the capillary pressure in the fractures. The reduced capillarypressure improves the flow of the hydrocarbon material through thefractures. Additionally, it is believed that the materials of theinvention, once adsorbed or bonded to the rock surfaces, will improvewater drainage rates to help reduce existing water blocks as well as toreduce the formation of water blocks.

The invention provides several advantages over conventional recoverymethods. For example, by adsorbing or bonding the surface activematerials of the invention to the rock surfaces of the subterraneanformation, these surface active materials are not removed with thehydrocarbon material, as are conventional surfactants. Additionally, thematerials of the invention are less likely to be washed away by themovement of the fracking fluid through the formation, as can occur withconventional surfactants.

In a first exemplary method of the invention, after the well bore isdrilled, a treatment fluid of the invention containing at least oneorganometallic material is injected into the subterranean formation. Thetreatment fluid can be injected either before or after the frackingfluid. In one non-limiting embodiment of the invention, the treatmentfluid is injected prior to the injection of the fracking fluid. Thetreatment fluid can be prepared, for example, by mixing a concentratedsolution of the organometallic material with a carrier fluid.Preferably, the organometallic material includes one or more labilegroups (M-OR bonds) capable of bonding, for example via a condensationreaction, with active silanol groups and/or Si—O—Si groups on the rocksurface to form a stable Si—O-M bond to attach the organometallicmaterial to the rock surface. Other reactive groups can be used toattach other functional ligands, such as hydrocarbon or fluorocarbongroups.

The organometallic material preferably is derived from an organo metal,such as those in which the metal has electrons in the f electronorbital, such as metals selected from Period 6 of the Periodic Table ofelements (lanthanide series). Other examples of suitable metals includeLa, Hf, Ta, and W, with Ta being preferred. An example of anothersuitable metal is niobium. The organo portion of the metal is preferablyan alkoxide containing from 1 to 18, preferably 2 to 8 carbon atoms suchas ethoxide, propoxide, isopropoxide, butoxide, isobutoxide and tertiarybutoxide. The alkoxides may be in the form of simple esters andpolymeric forms of the esters. For example, with the preferred metal Ta,the simple esters would be Ta(OR)₅ where R is C₁ to C₁₈ alkyl. Polymericesters would be obtained by condensation of the alkyl esters mentionedabove and typically would have the structure RO-[Ta(OR)₃—O—]_(x)R whereR is defined above and x is a positive integer. Besides alkoxides, otherligands can be present such as acetyl acetonates. Also, ligands such aschloride, acetylacetonate, alkanolamine and lactate, etc. may bepresent.

The organometallic material may be dissolved or dispersed in a diluent(carrier fluid). Examples of suitable diluents are alcohols such asmethanol, ethanol and propanol, aliphatic hydrocarbons, such as hexane,isooctane and decane, ethers, for example, tetrahydrofuran anddialkylethers such as diethylether.

Also, adjuvant materials may be present in the treatment fluid. Examplesinclude stabilizers such as sterically hindered alcohols and acids,surfactants and anti-static agents. The adjuvants if present are presentin amounts of up to 30 percent by weight based on the non-volatilecontent of the composition.

The concentration of the organometallic material in the composition isnot particularly critical but is usually at least 0.01 millimolar,typically from 0.01 to 100 millimolar, and more typically from 0.1 to 50millimolar.

The organometallic treatment fluid can be obtained by mixing all of thecomponents at the same time with low shear mixing or by combining theingredients in several steps. The organometallic compounds describedabove are reactive with moisture, and care should be taken that moistureis not introduced with the diluent or adjuvant materials and that mixingis conducted in a substantially anhydrous atmosphere.

Without being limited by theory, it is believed that the organometallicmaterial bonds with the rock surface to form a polymeric metal oxidefilm, which may have unreacted alkoxide and hydroxyl groups forsubsequent reaction and possible covalent bonding with an optionaloverlayer material, as described below.

Although not intending to be bound by any theory, it is believed thepolymeric metal oxide is of the structure:

[M(O)_(x)(OH)_(y)(OR)_(z)]_(n)

where M is the metal of the invention, R is an alkyl group containingfrom 1 to 30 carbon atoms; x+y+z=V, the valence of M; x is at least 1, yis at least 1, z is at least 1; x=V−y−z; y=V−x−z; z=V−x−y; n is greaterthan 2, such as 2 to 1000.

As mentioned above, after the treatment fluid containing theorganometallic material (i.e., a first treatment fluid) is injected intothe formation to attach the polymeric metal oxide film to the rocksurface, an optional second treatment fluid can be injected into theformation. The second treatment fluid contains a material capable ofconnecting, for example chemically bonding, with the polymeric metaloxide film to form an overlayer or a different film. Such an overlayermaterial preferably contains groups that are reactive with alkoxideand/or hydroxyl groups, such as hydroxyl groups or acid groups orderivatives thereof.

Preferably, the reactive material of the second treatment fluid is anorganic acid or a derivative thereof. The acid may be a carboxylic acid,a sulfonic acid or a phosphorus acid, such as a phosphoric acid, aphosphonic acid, or a phosphinic acid. By derivatives of acids are meantfunctional groups that perform similarly as acids such as acid salts,acid esters and acid complexes. The organo group of the acid may bemonomeric, oligomeric or polymeric. For example, the organo acid may bea monomeric, phosphoric, phosphonic or phosphinic acid.

Examples of monomeric phosphoric acids are compounds or a mixture ofcompounds having the following structure:

(RO)_(x)P(O)(OR′)_(y)

wherein x is 1-2, y is 1-2 and x+y=3, R is a radical having a total of1-30, preferably 6-18 carbons, where R′ is H, a metal such as an alkalimetal, for example, sodium or potassium, alkyl including substitutedalkyl having 1 to 50 carbons; preferably 1 to 4 carbons such as methylor ethyl, including substituted aryl having 6 to 50 carbons; preferably,a portion of R′ is H. The organic component of the phosphoric acid (R)can be aliphatic (e.g., alkyl having 2-20, preferably 6-18 carbon atoms)including an unsaturated carbon chain (e.g., an olefin), or can be arylor aryl-substituted moiety.

Example of monomeric phosphonic acids are compounds or mixture ofcompounds having the formula:

wherein x is 0-1, y is 1, z is 1-2 and x+y+z is 3. Preferably, R and R″are each independently a radical having a total of 1-30, preferably 6-18carbons. R′ is H, a metal, such as an alkali metal, for example, sodiumor potassium or an amine or alkyl including substituted alkyl having 1to 50 carbon atoms, preferably lower alkyl having 1-4 carbons such asmethyl or ethyl, or aryl including substituted aryl having 6 to 50carbons. Preferably at least a portion of R′ is H. The organic componentof the phosphonic acid (R and R″) can be aliphatic (e.g., alkyl having2-20, preferably 6-18 carbon atoms) including an unsaturated carbonchain (e.g., an olefin), or can be an aryl or aryl-substituted moiety.

Example of monomeric phosphinic acids are compounds or mixture ofcompounds having the formula:

wherein x is 0-2, y is 0-2, z is 1 and x+y+z is 3. Preferably, R and R″are each independently radicals having a total of 1-30, preferably 6-18carbons. R′ is H, a metal, such as an alkali metal, for example, sodiumor potassium or an amine or alkyl including substituted alkyl having 1to 50 carbon atoms, preferably lower alkyl having 1-4 carbons, such asmethyl or ethyl, or aryl including substituted aryl having 6 to 50carbons. Preferably a portion of R′ is H. The organic component of thephosphinic acid (R, R″) can be aliphatic (e.g., alkyl having 2-20,preferably 6-18 carbon atoms) including an unsaturated carbon chain(e.g., an olefin), or can be an aryl or aryl-substituted moiety.

Examples of organo groups which may comprise R and R″ include long andshort chain aliphatic hydrocarbons, aromatic hydrocarbons andsubstituted aliphatic hydrocarbons and substituted aromatichydrocarbons. Examples of substituents include carboxyl such ascarboxylic acid, hydroxyl, amino, imino, amido, thio, cyano, and fluoro.

Representative of the organophosphorous acids are as follows: aminotrismethylene phosphonic acid, aminobenzylphosphonic acid, 3-aminopropyl phosphonic acid, O-aminophenyl phosphonic acid, 4-methoxyphenylphosphonic acid, aminophenylphosphonic acid, aminophosphonobutyric acid,aminopropylphosphonic acid, benzhydrylphosphonic acid, benzylphosphonicacid, butylphosphonic acid, carboxyethylphosphonic acid,diphenylphosphinic acid, dodecylphosphonic acid, ethylidenediphosphonicacid, heptadecylphosphonic acid, methylbenzylphosphonic acid,naphthylmethylphosphonic acid, octadecylphosphonic acid, octyiphosphonicacid, pentylphosphonic acid, phenylphosphinic acid, phenylphosphonicacid, bis-(perfluoroheptyl)phosphinic acid, perfluorohexyl phosphonicacid, styrene phosphonic acid, dodecyl bis-1,12-phosphonic acid,poly(hexafluoropropyl)phosphonic acid.

In addition to the monomeric organophosphorous acids, oligomeric orpolymeric organophosphorous acids resulting from self-condensation ofthe respective monomeric acids may be used.

To provide hydrophobic properties to the overlayer, the organic acid orderivative thereof may be a fluorinated material, typically aperfluorinated oligomer having a number average molecular weight of lessthan 2000. The perfluorinated material can be a perfluorinatedhydrocarbon of the following structure:

R_(f)—(CH₂)_(p)—X

where R_(f) is a perfluorinated alkyl group or a perfluorinated alkyleneether group and p is 2 to 4, preferably 2.

Examples of perfluoroalkyl groups are those of the structure:

where Y is F or C_(n)F_(2n+1); m is 4 to 20 and n is 1 to 6.

Examples of perfluoroalkylene ether groups are those of the structure:

where A is an oxygen radical or a chemical bond; n is 1 to 6; Y is F orC_(n)F_(2n+1); W is H, F, C_(n)F_(2n) or C_(n)F_(2n); b is 2 to 10, m is0 to 6, and p is 0 to 18.

X is an acid group or an acid derivative. Preferably, X is:

where R and R″ are a hydrocarbon or substituted hydrocarbon radicalhaving up to 200, such as 1 to 30 and 6 to 20 carbons, R can alsoinclude the perfluoroalkyl groups mentioned above, and R′ is H, a metalsuch as potassium or sodium or an amine or an aliphatic radical, forexample, alkyl including substituted alkyl having 1 to 50 carbons,preferably lower alkyl having 1 to 4 carbons such as methyl or ethyl, oraryl including substituted aryl having 6 to 50 carbons.

Examples of fluorinated materials are esters of perfluorinated alcoholssuch as the alcohols of the structure:

where Y is F or C_(n)F_(2n+1); m is 4 to 20 and n is 1 to 6.

Examples of suitable esters are stearates and citrates of such alcohols.Such materials are available from E. I. du Pont de Nemours and Companyunder the trademark ZONYL FTS and ZONYL TBC.

The overlayer material (e.g., the organophosphorous material) can bedissolved in a liquid diluent (carrier fluid). The concentration of theoverlayer material is typically dilute, for example, no greater than 10percent on a weight/volume basis for solid overlayer material and 10percent on a volume/volume basis for oil and liquid overlayer material,and preferably is within the range of 0.01 to 1.0 percent. Thepercentages are based on total weight or volume of the solution.

Examples of suitable diluents are hydrocarbons, such as hexane isooctaneand toluene; ketones, such as methyl ethyl ketone; alcohols, such asmethanol and ethanol; ethers, such as tetrahydrofuran. Fluorinatedsolvents such as nonafluorobutylmethyl ether and fluorinated solventsavailable as HFE-7100, supplied by 3M Innovative Products andperfluorinated ethers supplied by Solvay Solexis under the trademarkGALDEN are preferred for use with the fluorinated material. Thefluorinated solvents can be used in admixtures with the other solventsmentioned above. The fluorinated solvents or diluents are different fromthe fluorinated materials in that the fluorinated solvents or diluentsare not film formers, whereas the fluorinated materials are.

The resultant layer typically is thin, having a thickness of about10-100 nanometers or less. The fluorinated overlayers are hydrophobic,having a water contact angle greater than 70°, typically from 75-130°.The water contact angle can be determined using a contact anglegoniometer such as a TANTEC contact angle meter Model CAM-MICRO.

In the above described method, the organometallic material-containingtreatment fluid of the invention is first injected into the formation toadhere the organometallic material to the rock surface. This mayoptionally, but not necessarily, be followed by injection of the secondorganophosphorous material-containing treatment fluid to attach theorganophosphorous material to the previously adhered organometallicmaterial. After which, the fracking fluid is injected in conventionalmanner. The adhered material of the invention reduces the capillarypressure in the fractures to promote the flow of the hydrocarbonmaterial and also to help prevent water blocks.

However, in another embodiment of the invention, a treatment fluidcontaining a surface modifying material as described below is injectedinto the formation rather than the fluids described above. This surfacemodifying material is capable of adhering or bonding with the rocksurface of the formation. The surface modifying material comprises thereaction product of a transition metal compound and a silicon-containingmaterial.

The transition metal material includes a compound preferably derivedfrom niobium, lanthanum, or transition metals that have electrons in thef electron orbital, such as metals selected from Period 6 (lanthanideseries) of the Periodic Table of elements. Examples of suitable metalsinclude La, Hf, Ta, and W, with Ta being preferred. The ligandassociated with the transition metal may be an alkoxide containing from1 to 18, preferably 2 to 8 carbon atoms such as ethoxide, propoxide,isopropoxide, butoxide, isobutoxide and tertiary butoxide. The alkoxidesmay be in the form of simple esters and polymeric forms of the esters.For example, with the preferred metal Ta, the simple esters would beTa(OR)₅ where R is C₁ to C₁₈ alkyl. Polymeric esters would be obtainedby condensation of the alkyl esters mentioned above and typically wouldhave the structure RO-[Ta(OR)₃—O-]_(x)R where R is defined above and xis a positive integer. Besides alkoxides, examples of other ligands arehalides, particularly chloride, acetyl acetonates, alkanolamine andlactate. Mixed ligands such as alkoxides and acetyl acetonates may alsobe present. TaC1₅ is a preferred transition metal compound.

Examples of silicon-containing materials are organosilicon-containingmaterials such as these having the formula:

R¹ _(4-x)SiA_(x) or (R¹ ₃Si)_(y)B

and organo(poly)siloxanes and organo(poly)silazanes containing units ofthe formula:

where R¹ are identical or different and are a hydrocarbon radicalincluding a substituted, hydrocarbon radical such as halo, particularlyfluoro-substituted hydrocarbon radical containing from 1 to 100, such as1 to 20 carbon atoms and 1 to 12, preferably 1 to 6 carbon atoms. A inthe above structural formula may be hydrogen, a halogen such aschloride, OH, OR² or

B in the above structural formula can be NR³ _(3-y). R² is a hydrocarbonor substituted hydrocarbon radical containing from 1 to 12, typically 1to 4 carbon atoms. R³ is hydrogen or has the same meaning as R¹. x is 1,2 or 3, y is 1 or 2.

Preferably, R¹ is a fluoro-substituted hydrocarbon. Examples of suchfluoro substituted hydrocarbons are those of the structure:

where Y is F or C_(n)F_(2n+1); m is 4 to 20 and n is 1 to 6, R² is alkylcontaining from 1 to 4 carbon atoms and p is 0 to 18. Also,fluoro-substituted hydrocarbons may be of the structure:

where A is an oxygen radical or a chemical bond; n is 1 to 6, y is F orC_(n), F_(2n); b is at least 1, such as 2 to 10; m is 0 to 6 and p is 0to 18.

The organosilicon material can also be an organo(poly)siloxane or anorgano(poly)silazane such as those having the structural units:

where R¹ is a hydrocarbon or substituted hydrocarbon having from 1 to12, preferably 1 to 6 carbon atoms such as methyl and ethyl and R³ ishydrogen or a hydrocarbon or substituted hydrocarbon having 1 to 12,preferablyl to 6 carbon atoms. The organo(poly)siloxane may containadditional units of the formula:

R⁵ ₂SiO₂

where R⁵ is a halogen such as a chloro or fluoro substituent.

The organo(poly)siloxane and organo(poly)silazane typically have anumber average molecular weight of at least 400, usually between 1000and 5,000,000.

The reaction products can be prepared by mixing the transition metalcompound and the silicon-containing material in a closed system (i.e.,low humidity) to avoid hydrolysis of the reactants. Reaction can occurneat or in the presence of a nonreactive solvent such as chlorinated orfluorinated solvent, for example, methylene chloride. Reaction occursrapidly at room temperature and is complete from 1 to 30 minutesdepending upon the reactants. Also, once again depending upon thereactants, heat can be used to initiate and complete the reaction.Solvent can be removed by evaporation and the reaction product can beredissolved in a suitable solvent such as an alcohol, for example,ethanol or propanol, for application to the substrate. The mole ratio ofthe organosilicon-containing material to transition metal compound istypically from 100:1 to 1:100, preferably from 1:1 to 10:1 depending onthe valence of the transition metal compound. For example, the molarratio of organosilicon compound to Ta(V) is typically 5 to 1.

The reaction product or the partially reacted reaction product or themixture of reactants may be contained in an organic diluent. Examples ofsuitable diluents are alcohols such as methanol, ethanol and propanol,aliphatic hydrocarbons such as hexane, isooctane and decane, ethers, forexample, tetrahydrofuran, and dialkylethers such as diethylether. Tomake the resulting complex more stable, the ligands can be modified(e.g. by exchanging 2-ethylhexanol ligands for isopropoxide ligands) onthe transition metal specie.

Also, adjuvant materials may be present. Examples include stabilizerssuch as sterically hindered alcohols and acids or surfactants. Also,additional active agents may also be incorporated into the fluid, suchas antibacterial agents, anti-static compounds, lubricants, olfactoryagents, etc. The adjuvants if present are present in amounts of up to 30percent by weight based on the non-volatile content of the composition.

The concentration of the reaction product in the composition is notparticularly critical but is usually at least 0.01 millimolar, typicallyfrom 0.01 to 100 millimolar, and more typically from 0.1 to 50millimolar.

The composition can be obtained by mixing all of the components at thesame time with low shear mixing or by combining the ingredients inseveral steps. The reaction product is reactive with moisture, and careshould be taken that moisture is not introduced with the diluent oradjuvant materials and that mixing is conducted in a substantiallyanhydrous atmosphere.

The transition metal material and the silicon-containing material aretypically dissolved or dispersed in organic diluent such as describedabove. The concentrations of the separate materials in the diluent areat least 0.1 millimolar, typically from 0.01 to 100 millimolar, and moretypically from 0.1 to 50 millimolar. Adjuvants such as those describedabove can be included in one or both of the dispersions or solutions.

As will be appreciated by one skilled in the art, the number of reactiveSi—OH groups on the surface of the rock formation may likely be low dueto self-condensation reactions that have occurred over the course ofmillennia. Therefore, in another aspect of the invention, astabilization fluid can be injected into the subterranean formation, forexample prior to injection of the treatment fluids and/or the frackingfluid. The stabilization fluid contains a stabilization material capableof increasing the density of silanol groups on the rock surface and/orstabilizing the silanol groups against self-condensation. An exemplarystabilization fluid is an aqueous solution containing divalent metalcations.

The following example is intended to illustrate the invention, andshould not be construed as limiting the invention as many differentembodiments can be made without departing from the spirit and scope ofthe invention. Therefore, the invention is not limited except as definedin the claims.

EXAMPLE

This example illustrates the application of coating compositions of theinvention onto carbonaceous shale substrates and the effect of thecoating compositions on the contact angle measurement of a water dropletsubsequently applied onto the coated carbonaceous shale substrates.

The substrates were made by cleaving a carbonaceous shale block(commercially available from Ward's Natural Science) into flat pieces.The shale substrates simulate the rock surfaces of a hydrocarbon-bearingsubterranean rock formation. No pre-cleaning or soaking with reagentswas performed on the cleaved substrates prior to coating the substratesas described below.

The percent values of components used in this example are in volumepercent, unless otherwise indicated. The reported contact angle valueswere measured using a TANTEC Contact Angle Meter, Model CAM-MICRO(commercially available from Tantec Inc.).

Materials Formulation A

1.5% Gelest XG-2110 (a heptadecafluorodecyl-terminatedpoly(dimethylsiloxane) having a reported molecular weight in the rangeof 6,000 to 7,000 and commercially available from Gelest, Inc.)

0.5% Gelest DMS-S15 (a silanol-terminated poly(dimethylsiloxane) havinga reported molecular weight in the range of 2,000 to 3,500 andcommercially available from Gelest, Inc.)

0.2% tantalum (V) ethoxide

Soltrol-10 solvent (an isooctane blend commercially available fromChevron Phillips Chemical Company LP)

Formulation B

1.5% Gelest ALT-143 (a poly(n-octylmethylsiloxane) commerciallyavailable from Gelest, Inc.)

0.5% Gelest DMS-S15 (a silanol-terminated poly(dimethylsiloxane) havinga reported molecular weight in the range of 2,000 to 3,500 andcommercially available from Gelest, Inc.)

0.2% tantalum (V) ethoxide

Soltrol-10 solvent (an isooctane blend Commercially available fromChevron Phillips Chemical Company LP)

Procedure

The cleaved carbonaceous shale substrates were dipped into eitherFormulation A or Formulation B for 30 minutes, removed, then rinsed withfresh hexanes. Then the contact angle of water droplets on thesubstrates was measured.

Results

Control: the carbonaceous shale substrates (i.e., cleaved from the blockbut not dipped in either Formulation A or Formulation B) provided anaverage contact angle of less than or equal to 10. The water dropletswere almost immediately absorbed into the shale substrates.

Formulation A: the shale substrates immersed in Formulation A providedan average contact angle of 124 degrees.

Formulation B: the shale substrates immersed in Formulation B providedan average contact angle of 120 degrees.

As can be seen from the above results, a significant change in watercontact angle was achieved by the application of the exemplary coatingformulations onto the surface of the carbonaceous shale substratescompared to the contact angle measured on the surface of the non-coatedshale substrates. The hydrophobicity of the carbonaceous shale surfacewas increased by application of the coatings. Applicants believe asimilar result (i.e., an increase in the hydrophobicity of the rocksurfaces of the fissures formed during the fracking operation) will beobtained in accordance with the practice of the invention by injectingthe compositions of the invention into the hydrocarbon-bearingsubterranean rock formations, although the increase in hydrophobicitymay not necessarily be to the same extent as in the examples describedabove. However, any increase in hydrophobicity will aid in the flow ofhydrocarbon material through the fissures and the drainage of waterblocks from the fissures.

It will be readily appreciated by one of ordinary skill in the art thatmodifications may be made to the invention without departing from theconcepts disclosed in the foregoing description. Accordingly, theparticular embodiments described in detail herein are illustrative onlyand are not limiting to the scope of the invention, which is to be giventhe full breadth of the appended claims and any and all equivalentsthereof.

This application is a continuation of application Ser. No. 14/197,258filed Mar. 5, 2014 entitled “Methods for Recovering HydrocarbonMaterials From Subterranean Formations” which published as U.S. PatentPublication No. 2015/0252656 on Sep. 10, 2015, which is incorporatedherein by reference in this application serial number Above paragraphs[0001]-[0078] of this patent application Ser. No. 15/407,878 filed Jan.17, 2017 are copied from publication 2015/0252656.

1. A method for recovering hydrocarbon material from a subterraneanformation, comprising: introducing at least one treatment fluid into thesubterranean formation, wherein the at least one treatment fluidcomprises at least one organometallic material which is dissolved in adiluent.
 2. The method of claim 1, comprising the steps of: introducinga first treatment fluid into the subterranean formation, the firsttreatment fluid comprising an organometallic material; and introducing asecond treatment fluid into the subterranean formation, the secondtreatment fluid comprising an organophosphorous material which isdissolved in a non-aqueous diluent.
 3. (canceled)
 4. (canceled) 5.(canceled)
 6. The method of claim 2, wherein the organometallic materialcomprises a metal selected from the group consisting of aluminum,titanium, zirconium, lanthanum, hafnium, tungsten, niobium, andtantalum.
 7. The method of claim 2, wherein the organometallic materialcomprises a C1 to C18 alkoxide group.
 8. (canceled)
 9. The method ofclaim 2, wherein the organophosphorous material comprises an acidselected from the group consisting of organophosphoric acid,organophosphonic acid, organophosphinic acid, and derivatives thereof.10. (canceled)
 11. The method of claim 2, wherein the organophosphorousmaterial comprises at least one group selected from an aliphatic group,an olefinic group, and an aryl-substitute group.
 12. The method of claim2, further comprising introducing a stabilization fluid comprising anaqueous solution including divalent metal cations into the subterraneanformation prior to introducing the first treatment fluid.
 13. (canceled)14. A method for recovering hydrocarbon material from a subterraneanformation, comprising: introducing at least one treatment fluid into thesubterranean formation, wherein the at least one treatment fluidcomprises a material which is dissolved in a non-aqueous diluent andwhich material is comprising the reaction product of: (a) a transitionmetal compound; and (b) a silicon-containing material
 15. The method ofclaim 14, wherein the transition metal compound includes a transitionmetal selected from the group consisting of niobium, lanthanum, andtransition metals having electrons in the f orbital.
 16. (canceled) 17.The method of claim 14, wherein the transition metal compound includes atransition metal selected from the group consisting of La, Hf, Ta, W andNb.
 18. The method of claim 14, wherein the transition metal compoundincludes ligands selected from alkoxide, halide, keto acid, amine, andacylate.
 19. (canceled)
 20. The method of claim 14, wherein thesilicon-containing material has a formula selected from:R¹ _(4-x)SiA_(x) or (R¹ ₃Si)_(y)B or an organo(poly)siloxane and anorgano(poly)silazane containing units of the formula:

where: R¹ are identical or different and are a hydrocarbon orsubstituted hydrocarbon radical containing from 1 to 100 carbon atoms,

A is hydrogen, halogen, OH, OR² or B is NR³ _(3-y), R² is a hydrocarbonor substituted hydrocarbon radical containing from 1 to 12 carbon atoms,R³ is hydrogen or is the same as R¹ x is 1, 2 or 3, and y is 1 or
 2. 21.The method of claim 20, wherein the silicon-containing material has thefollowing formula:R¹ _(4-x)SiA_(x) where R¹ is a fluoro-substituted hydrocarbon and A isOR².
 22. The method of claim 21, wherein R¹ is of the structure:

where Y is F or C_(n)F_(2n+1); m is 4 to 20; n is 1 to 6; R² is alkylcontaining from 1 to 4 carbon atoms; and p is 0 to
 18. 23. The method ofclaim 21, wherein the fluoro-substituted hydrocarbon is of thestructure:

where A is an oxygen radical or a chemical bond; n is 1 to 6; Y is F orC_(n)F_(2n+1); b is at least 1; m is 0 to 6 and p is 0 to
 18. 24.(canceled)
 25. The method of claim 14, wherein the silicon-containingmaterial is an organo(poly)siloxane or an organo(poly)silazane andwherein the organo(poly)siloxane and organo(poly)silazane include unitsof the formula:

where R¹ are identical or different and are a hydrocarbon or substitutedhydrocarbon radicals containing from 1 to 12 carbon atoms and R³ ishydrogen or is the same as R¹.
 26. The method of claim 25, wherein theorgano(poly)siloxane contains additional units of the formula: R⁵ ₂SiO₂where R⁵ contains a halogen.
 27. (canceled)
 28. The method of claim 25,wherein the organo(poly)siloxane and organo(poly)silazane have a numberaverage molecular weight of at least
 400. 29. (canceled)
 30. The methodof claim 14, further comprising introducing a stabilization fluidcomprising an aqueous solution including divalent metal cations into thesubterranean formation prior to introducing the treatment fluid.
 31. Amethod for recovering hydrocarbon material from a subterraneanformation, comprising: introducing a first treatment fluid comprisingdivalent metal cations into the subterranean formation; and introducinga second treatment fluid into the subterranean formation, wherein thesecond treatment fluid comprises a material which is dissolved in anon-aqueous diluent and which material is comprising the reactionproduct of: (a) a transition metal compound; and (b) asilicon-containing material.